Method for the production of monomers useful in the manufacture of semiconductive polymers

ABSTRACT

The instant invention relates to a new method for the synthesis of monomers and their use inter alia in the manufacture of semiconductive polymers. Monomers, in particular, asymmetric monomers, such as asymmetric fluorene compounds, are valuable material in the manufacture of semiconductive polymers. The know methods for producing asymmetric monomers, such as asymmetric fluorene compounds, are expensive due to the formation of by-products. 
     The method according to the present invention avoids the formation of such by-products and is described in more detail in claims  1  to  14.

RELATED APPLICATIONS

This application is a national stage application (under 35 U.S.C. 371)of PCT/2003/012022 filed Oct. 29, 2003 which claims benefit to EuropeanPatent Application 02024183.2 filed Oct. 30, 2002.

FIELD OF THE INVENTION

This invention relates to a new method for the synthesis of monomers andtheir use inter alia in the manufacture of semiconductive polymers.

BACKGROUND OF THE INVENTION

Electroactive polymers are now frequently used in a number of opticaldevices such as in polymeric light emitting diodes (“PLEDs”) asdisclosed in WO 90/13148, photovoltaic devices as disclosed in WO96/16449 and photodetectors as disclosed in U.S. Pat. No. 5,523,555. Oneclass of electroluminescent polymers are polyfluorenes as disclosed in,for example, Adv. Mater. 2000 12(23) 1737-1750. These polyfluorenes havethe advantages of being soluble in conventional organic solvents andhave good film forming properties. Furthermore, fluorene monomers areamenable to Suzuki or Yamamoto polymerisation which enables a highdegree of control over the regioregularity of the resultant polymer andthe formation of block copolymers wherein different blocks havedifferent functions as disclosed in WO 00/55927.

Each fluorene repeat unit of these polyfluorenes is normally providedwith two 9-substituents to modifiy the properties of the polymer. Forexample, alkyl groups have been used as 9-substituents for the purposeof increasing the solubility of the polymer. Other substituents, such asphenyl, have also been used.

The two 9-substituents are often the same for simplicity of manufacture,however this means that the fluorene repeat unit is symmetric which hasbeen found to be problematic in that polymers comprising symmetricalfluorene repeat units have a tendency to aggregate.

To overcome this problem, efforts have been directed towards productionof asymmetric fluorene monomers, i.e. fluorene monomers wherein the two9-substituents are different, as disclosed in WO 00/22026 and DE19846767. Processes disclosed in these documents include reaction offluorenone or biphenyl-2-carboxylic acid ester with two differentorganometallics.

Biphenyl-2-amides are known—see for example WO 00/03743 and U.S. Pat.No. 6,329,534. However, these disclosures do not teach such carboxamidescomprising polymerisable groups, asymmetric substitution or a method offorming monomers therefrom. Tetrahedron Letters 22(39), 3815-3818, 1981,describes a process of reacting N-methoxy amides with organometallicreagents to form ketones. The reaction proceeds via a 5-memberedintermediate that is resistant to over-reaction to form an alcohol. Thisdisclosure is not concerned with the formation of asymmetric systems,polycyclic systems or monomers.

SUMMARY OF THE INVENTION

The present inventors have found that the prior art methods of formingasymmetric compounds, in particular asymmetric fluorene compounds, havedrawbacks. When an ester starting material is used, the inventors havefound that some of the starting material may not react at all with thefirst organometallic, and the proportion that does react may go on toreact with a second equivalent resulting in a symmetric fluorene.Additional by-products may also form. Thus, the desired ketoneintermediate is not only present in low quantities, it is also difficultto separate from the other products and residual starting material.

It is therefore a purpose of the present invention to provide a materialfor production of an asymmetric monomer that is not susceptible toover-reaction to form a symmetric monomer and that does not presentdifficulties in isolating the desired product. It is a further purposeof the invention to provide a method of forming a monomer via use ofsaid material.

The present inventors have devised a method of forming polycycliccompounds with asymmetric substituents, in particular compounds suitablefor use as monomers, via an amide starting material. In addition to thereaction of the amide, the method of the present invention includes thefurther steps of reacting the resultant ketone with a further equivalentof a different organometallic reagent and the yet further step of a ringclosing elimination reaction.

Accordingly, in a first aspect the invention provides a method accordingto scheme 1 of forming a compound of formula (IV):

said method comprising the steps of:

-   -   a) reacting a compound of formula (I) with a compound of formula        S¹-M to give a compound of formula (II);    -   b) reacting the compound of formula (II) with a compound of        formula S²-M to give a compound of formula (III); and    -   c) eliminating H₂X from the compound of formula (III) to give a        compound of formula (IV).        wherein

Ar¹ and Ar² are independently selected from optionally substituted arylor heteroaryl groups;

X is selected from O, S, NH and NR;

L is a bond or a linking group of 1, 2 or 3 atoms,

R and R¹ are independently selected from optionally substituted alkyl,alkylaryl, arylalkyl, aryl and heteroaryl groups;

R² is selected from the group consisting of alkoxy, aryloxy,arylalkyloxy, alkylaryloxy, alkylthio, arylthio, alkylarylthio,arylalkylthio;

H is bound to a carbon atom C′ of Ar²;

C′ and the carbon atom of C═X are separated by 3-5 atoms;

S¹ and S² are each selected from optionally substituted alkyl, aryl orheteroaryl groups;

M comprises a metal; and

M is linked to S¹ and S² by a carbon-metal bond.

Preferably, alkyl is C₁-C₂₀-alkyl which can be each straight-chain,branched or cyclic, where one or more non-adjacent CH2 groups may bereplaced by oxygen, sulphur, —CO—, —COO—, —O—CO—, NR¹⁰—,—(NR¹¹R¹²)^(+-A) ⁻ or —CONR¹³—, in particular preferred methyl, ethyl,n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl,s-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-octyl or cyclooctyl, andR¹⁰, R¹¹, R¹², R¹³ are identical or different and are hydrogen or analiphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms.

Preferably, arylalkyl is C₇-C₂₀-arylalkyl, where one or morenon-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—,—O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, in particular preferredo-tolyl, m-tolyl, p-tolyl, 2,6-dimethylphenyl, 2,6-diethylphenyl,2,6-di-i-propylphenyl, 2,6-di-t-butylphenyl, o-t-butylphenyl,m-t-butylphenyl or p-t-butylphenyl, and R¹⁰, R¹¹, R¹², R¹³ are identicalor different and are hydrogen or an aliphatic or aromatic hydrocarbonradical having 1 to 20 carbon atoms.

Preferably, alkylaryl is C₇-C₂₀-alkylaryl, where one or morenon-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—,—O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, in particular preferredbenzyl, ethylphenyl, propylphenyl, diphenylmethyl, triphenylmethyl ornaphthalinylmethyl, and R¹⁰, R¹¹, R¹², R¹³ are identical or differentand are hydrogen or an aliphatic or aromatic hydrocarbon radical having1 to 20 carbon atoms.

Preferably, aryl is C₆-C₂₀-aryl, in particular preferred phenyl,biphenyl, naphthyl, anthracenyl, triphenylenyl,[1,1′;3′,1″]terphenyl-2′-yl, binaphthyl or phenanthreny.l

Preferably, heteroaryl is C₅-C₂₀-heteroaryl, in particular preferred2-pyridyl, 3-pyridyl, 4-pyridyl, chinolinyl, isochinolinyl, acridinyl,benzochinolinyl or benzoisochinolinyl. Preferably, alkoxy isC₁-C₂₀-alkoxy, where one or more non-adjacent CH2 groups may be replacedby oxygen, sulphur, —CO—, —COO—, —O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or—CONR¹³—, in particular preferred methoxy, ethoxy, n-propoxy, i-propoxy,n-butoxy, i-butoxy, s-butoxy or t-butoxy, and R¹⁰, R¹¹, R¹², R¹³ areidentical or different and are hydrogen or an aliphatic or aromatichydrocarbon radical having 1 to 20 carbon atoms.

Preferably, aryloxy is C₆-C₂₀-Aryloxy, in particular preferred phenoxy,naphthoxy, biphenyloxy, anthracenyloxy or phenanthrenyloxy.

Preferably, arylalkyloxy is C₇-C₂₀-arylalkyloxy where one or morenon-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—,—O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, and R¹⁰, R¹¹, R¹², R¹³ areidentical or different and are hydrogen or an aliphatic or aromatichydrocarbon radical having 1 to 20 carbon atoms.

Preferably, alkylaryloxy is C₇-C₂₀-alkylaryloxy, where one or morenon-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—,—O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, and R¹⁰, R¹¹, R¹², R¹³ areidentical or different and are hydrogen or an aliphatic or aromatichydrocarbon radical having 1 to 20 carbon atoms.

Preferably, alkylthio is C₁-C₂₀-alkylthio where one or more non-adjacentCH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—, —O—CO—,NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³— and R¹⁰, R¹¹, R¹², R¹³ are identicalor different and are hydrogen or an aliphatic or aromatic hydrocarbonradical having 1 to 20 carbon atoms.

Preferably, arylthio is C₆-C₂₀-arylthio.

Preferably, alkylarylthio is C₇₋C₂₀-alkylarylthio where one or morenon-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—,—O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, and R¹⁰, R¹¹, R¹², R¹³ areidentical or different and are hydrogen or an aliphatic or aromatichydrocarbon radical having 1 to 20 carbon atoms.

Preferably, arylalkylthio is C₇-C₂₀-arylalkylthio, where one or morenon-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—,—O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, and R¹⁰, R¹¹, R¹², R¹³ areidentical or different and are hydrogen or an aliphatic or aromatichydrocarbon radical having 1 to 20 carbon atoms.

Intermediate products (II) and (III) may or may not be isolated from thereaction mixture prior to the subsequent step according to the method ofthe first aspect of the invention.

Each aryl group Ar¹ and Ar² may comprise a monocyclic or fused ringsystem.

Preferably, Ar¹ and Ar² are each phenyl or substituted phenyl.

Preferably, X is O or S.

Preferably, L is a bond.

Preferably, R is C1-10 alkyl

Preferably, R¹ is C1-10 alkyl.

Preferably, R² is C1-10 alkoxy.

Preferably, M is lithium, zinc or Mg-Hal wherein Hal is a halide.

Preferably, S¹ and S² are independently selected from optionallysubstituted aryl or alkyl, in particular preferred S¹ and S² aredifferent from each other.

In one preferred embodiment of the first aspect of the invention, Ar¹and Ar² of the compound of formula (I) are each substituted with apolymerisable group P.

In a second preferred embodiment of the first aspect of the invention,there is a further step of providing each of Ar¹ and Ar² of the compoundof formula (II), (III) or (IV) with a polymerisable group P.

Preferably, each polymerisable group P is independently a leaving groupcapable of participating in a polycondensation reaction, more preferablya metal insertion reaction with a nickel or palladium complex catalyst.Most preferably, each P is independently selected from a halide,(preferably chlorine, bromine or iodine, most preferably bromine; aboron derivative group selected from a boronic acid group, a boronicester group and a borane group; or a moiety of formula —O—SO₂-Z whereinZ is selected from the group consisting of optionally substituted alkyland aryl.

The method of the first aspect of the invention preferably comprises thestep of polymerising the compound of formula (IV) by reaction ofpolymerisable group P.

According to one preferred method of polymerisation, each polymerisablegroup P is a halide and the compound of formula (IV) is polymerised in areaction mixture comprising a catalytic amount of a nickel (0) catalystsuitable for catalysing the polymerisation of the compound of formula(IV).

According to another preferred method of polymerisation, at least 1polymerisable group P is a boron derivative group and the compound offormula (IV) is polymerised in a reaction mixture comprising a catalyticamount of a palladium catalyst suitable for catalysing thepolymerisation of the compound of formula (IV), and a base sufficient toconvert the boron derivative functional groups into boronate anionicgroups.

The compound of formula (IV) may or may not be isolated from thereaction mixture in which it is formed prior to its polymerisation.

In a second aspect, the invention provides a method for the productionof an optical device or a component for an optical device, whichcomprises providing a substrate, producing a polymer in accordance withthe first aspect of the invention and depositing the polymer on thesubstrate. Preferably, the optical device comprises anelectroluminescent device.

In a third aspect, the invention provides an optionally substitutedcompound of formula (V):

wherein Ar¹, Ar², L, X, R¹ and R² are as defined in formula (I) ofScheme 1; P is independently selected from a halide, preferablychlorine, bromine or iodine, most preferably bromine, or a boronderivative group selected from a boronic acid group, a boronic estergroup and a borane group, H is bound to a carbon atom C′ of Ar²; and C′and the carbon atom of C═X are separated by 3-5 atoms.

Preferably, each Ar¹ and Ar² is phenyl or substituted phenyl.

Preferably, X is O, S.

Preferably, L is a bond.

Preferably, each P is independently selected from a halide or a boronderivative group selected from a boronic acid group, a boronic estergroup and a borane group.

Preferably, R¹ is C1-10 alkyl.

Preferably, R² is C1-10 alkoxy.

Preferably, the compound of the third aspect of the invention is acompound of formula (VI):

wherein P, R¹ and R² are as defined in formula (V) above.

The present inventors have surprisingly found that compounds of formula(IV) may be prepared according to the method of the invention withoutover-reaction to form symmetric compounds and with the product beingobtained in high purity. In particular, compounds of formula (IV) may beprepared using compounds of formula (VI).

Furthermore, the present inventors have surprisingly found that themethod of the present invention is effective with standardorganometallic reagents (such as organolithium or Grignard reagents)whereas the prior art methods may only be effective with the morereactive reagents such as organolithium. Finally, the present inventorshave found that a wider range of substituents S¹ and/or S² may beprovided by the method of the invention than by the aforementioned priorart methods. As a result, a straightforward route to a wider range ofasymmetric monomers is made available which in turn provides greaterflexibility in terms of synthesis of polymers and copolymers withimproved solubility, morphology, etc.

DETAILED DESCRIPTION OF THE INVENTION

The method of the invention may be employed to prepare symmetric orasymmetric compounds, in particular symmetric or asymmetric fluorenes,wherein both substituents are aromatic, in particular phenyl; bothsubstituents are aliphatic, in particular C1-10 branched or linearalkyl; or one substituent is aromatic and the other substituent isaliphatic. Accordingly, a wide range of materials with differingsubstituents, and therefore different electronic properties, may beprepared.

Examples of asymmetric compounds that may be formed according to thismethod include asymmetric fluorenes and asymmetric indenofluorenes asillustrated below:

The materials prepared in accordance with the invention may be useful asmonomers, in particular monomers for the preparation of electroactive,more particularly semiconducting, polymers. These polymers may behomopolymers or copolymers.

The monomers according to the invention preferably comprise only tworeactive groups P in order that linear polymers be produced, howevermonomers with more than two P groups, e.g. for production ofcross-linked polymers, are also within the scope of the invention.

The asymmetric monomers according to the invention may be formed from arange of combinations of groups S¹ and S² including, but not limited tothe following:

S¹=unsubstituted phenyl; S²=phenyl bearing one or more alkyl or alkoxysubstituents;

S¹ and S² are both phenyl, each bearing a different alkyl or alkoxysubstituent and/or the same alkyl or alkoxy groups substituted indifferent positions;

S¹=optionally substituted phenyl or heteroaryl; S²=optionallysubstituted alkyl;

S¹=optionally substituted phenyl; S²=optionally substituted heteroaryl.

The compound of formula (IV) according to the invention is preferably afluorene bearing substituents S¹ and S².

The polymers prepared using monomers according to the invention may behomopolymers or copolymers. A wide range of co-monomers forpolymerisation with the monomers of the invention will be apparent tothe skilled person. Examples of comonomers include triarylamines asdisclosed in, for example, WO 99/54385 and heteroaryl units as disclosedin, for example, WO 00/46321 and WO 00/55927.

Where the polymer according to the invention is a co-polymer, it maypossess the repeat unit of the invention with one or more differentco-repeat units. One class of co-repeat units is arylene repeat units,in particular: 1,4-phenylene repeat units as disclosed in J. Appl. Phys.1996, 79, 934; fluorene repeat units as disclosed in EP 0842208,trans-indenofluorene repeat units as disclosed in, for example,Macromolecules 2000, 33(6), 2016-2020; spirobifluorene repeat units asdisclosed in, for example EP 0707020; and stilbene repeat units(commonly known as “OPV” repeat units) as disclosed in WO 03/020790.Each of these repeat units is optionally substituted. Examples ofsubstituents include solubilising groups such as C₁₋₂₀alkyl or alkoxy;electron withdrawing groups such as fluorine, nitro or cyano; andsubstituents for increasing glass transition temperature (Tg) of thepolymer such as bulky groups, e.g. tert-butyl or optionally substitutedaryl groups.

Particularly preferred triarylamine repeat units for such copolymersinclude units of formulae 1-6:

X and Y may be the same or different and are substituent groups. A, B, Cand D may be the same or different and are substituent groups. It ispreferred that one or more of X, Y, A, B, C and D is independentlyselected from the group consisting of alkyl, aryl, perfluoroalkyl,thioalkyl, cyano, alkoxy, heteroaryl, alkylaryl and arylalkyl groups.One or more of X, Y, A, B, C and D also may be hydrogen. It is preferredthat one or more of X, Y, A, B, C and D is independently anunsubstituted, isobutyl group, an n-alkyl, an n-alkoxy or atrifluoromethyl group because they are suitable for helping to selectthe HOMO level and/or for improving solubility of the polymer.

Particularly preferred heteroaryl repeat units for such copolymersinclude units of formulae 7-24:

wherein R₃ and R₄ are the same or different and are each independently asubstituent group. Preferably, one or more of R₁, R₂, R₃ or R₄ may beselected from hydrogen, alkyl, aryl, perfluoroalkyl, thioalkyl, cyano,alkoxy, heteroaryl, alkylaryl, or arylalkyl. These groups are preferredfor the same reasons as discussed in relation to X, Y, A, B, C and Dabove. Preferably, for practical reasons, R₃ and R₄ are the same. Morepreferably, they are the same and are each a phenyl group.

wherein each R⁵ is independently selected from hydrogen, optionallysubstituted alkyl, alkoxy, aryl, heteroaryl, arylalkyl, alkylaryl,aryloxy, arylalkyloxy or alkylaryloxy.

Preferably, optionally substituted alkyl is C₁-C₂₀-alkyl, which can beeach straight-chain, branched or cyclic, where one or more non-adjacentCH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—, —O—CO—,NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, in particular preferred methyl,ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl,s-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-octyl or cyclooctyl, andR¹⁰, R¹¹, R¹², R¹³ are identical or different and are hydrogen or analiphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms.

Preferably, arylalkyl is C₇-C₂₀-arylalkyl, where one or morenon-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—,—O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, in particular preferredo-tolyl, m-tolyl, p-tolyl, 2,6-dimethylphenyl, 2,6-diethylphenyl,2,6-di-i-propylphenyl, 2,6-di-t-butylphenyl, o-t-butylphenyl,m-t-butylphenyl or p-t-butylphenyl, and R¹⁰, R¹¹, R¹², R¹³ are identicalor different and are hydrogen or an aliphatic or aromatic hydrocarbonradical having 1 to 20 carbon atoms.

Preferably, alkylaryl is C₇-C₂₀-alkylaryl, where one or morenon-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—,—O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR³—, in particular preferredbenzyl, ethylphenyl, propylphenyl, diphenylmethyl, triphenylmethyl ornaphthalinylmethyl, and R¹⁰, R¹¹, R¹², R¹³ are identical or differentand are hydrogen or an aliphatic or aromatic hydrocarbon radical having1 to 20 carbon atoms.

Preferably, aryl is C₆-C₂₀-aryl, in particular preferred phenyl,biphenyl, naphthyl, anthracenyl, triphenylenyl,[1,1′;3′,1″]terphenyl-2′-yl, binaphthyl or phenanthreny.l

Preferably, heteroaryl is C₅-C₂₀-heteroaryl, in particular preferred2-pyridyl, 3-pyridyl, 4-pyridyl, chinolinyl, isochinolinyl, acridinyl,benzochinolinyl or benzoisochinolinyl.

Preferably, alkoxy is C₁-C₂₀-alkoxy, where one or more non-adjacent CH2groups may be replaced by oxygen, sulphur, —CO—, —COO—, —O—CO—, NR¹⁰—,—(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, in particular preferred methoxy, ethoxy,n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy or t-butoxy, and R¹⁰,R¹¹, R¹², R¹³ are identical or different and are hydrogen or analiphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms.

Preferably, aryloxy is C₆-C₂₀-Aryloxy, in particular preferred phenoxy,naphthoxy, biphenyloxy, anthracenyloxy or phenanthrenyloxy.

Preferably, arylalkyloxy is C₇-C₂₀-arylalkyloxy where one or morenon-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—,—O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, and R¹⁰, R¹¹, R¹², R¹³ areidentical or different and are hydrogen or an aliphatic or aromatichydrocarbon radical having 1 to 20 carbon atoms.

Preferably, alkylaryloxy is C₇-C₂₀-alkylaryloxy, where one or morenon-adjacent CH2 groups may be replaced by oxygen, sulphur, —CO—, —COO—,—O—CO—, NR¹⁰—, —(NR¹¹R¹²)⁺-A⁻ or —CONR¹³—, and R¹⁰, R¹¹, R¹², R¹³ areidentical or different and are hydrogen or an aliphatic or aromatichydrocarbon radical having 1 to 20 carbon atoms.

The polymer may have hole transporting, electron transporting and/oremissive properties. The polymer may have one or more of theseproperties. Where the polymer has more than one of these properties,different properties may be provided by different segments of thepolymer, in particular segments of the polymer backbone as described inWO 00/55927 or pendant groups as described in WO 02/26859.Alternatively, if the polymer of the invention has only one or two ofthe properties of hole transport, electron transport and emission, itmay be blended with one or more further polymers having the remainingrequired property or properties.

Preferred methods for polymerisation of these monomers are Suzukipolymerisation as described in, for example, WO 00/53656 and Yamamotopolymerisation as described in, for example, T. Yamamoto,“ElectricallyConducting And Thermally Stable π-Conjugated Poly(arylene) s Prepared byOrganometallic Processes”, Progress in Polymer Science 1993, 17,1153-1205 or Stille coupling. For example, in the synthesis of a linearpolymer by Yamamoto polymerisation, a monomer having two reactive halidegroups P is used. Similarly, according to the method of Suzukipolymerisation, at least one reactive group P is a boron derivativegroup.

As alternatives to halogens as described above, leaving groups offormula —O—SO2Z can be used wherein Z is as defined above. Particularexamples of such leaving groups are tosylate, mesylate and triflate.

Suzuki polymerisation employs a Pd(0) complex or a Pd(II) salt.Preferred Pd(0) complexes are those bearing at least one phosphineligand such as Pd(Ph3P)4.

Another preferred phosphine ligand is tris(ortho-tolyl)phosphine, i.e.Pd(o-Tol)3.

Preferred Pd (II) salts include palladium acetate, i.e. Pd(OAc)2. Suzukipolymerisation is performed in the presence of a base, for examplesodium carbonate, potassium phosphate or an organic base such astetraethylammonium carbonate.

Yamamoto polymerisation employs a Ni(0) complex, for examplebis(1,5-cyclooctadienyl)nickel(0).

Suzuki polymerisation may be used to prepare regioregular, block andrandom copolymers. In particular, random copolymers may be prepared whenone reactive group P is a halogen and the other reactive group P is aboron derivative group.

Alternatively, block or regioregular, in particular AB, copolymers maybe prepared when both reactive groups of a first monomer are boron andboth reactive groups of a second monomer are halide.

Polymers made in accordance with the invention may be used in any of theaforementioned optical devices. In forming these devices, the polymermay deposited from solution by any one of a range of techniquesincluding in particular techniques such as spin-coating, inkjet printingas disclosed in EP 0880303, laser transfer as described in EP 0851714,flexographic printing, screen printing and doctor blade coating.

A PLED comprises an electroluminescent polymer between an anode and acathode and is supported on a substrate.

Optical devices tend to be sensitive to moisture and oxygen.Accordingly, the substrate preferably has good barrier properties forprevention of ingress of moisture and oxygen into the device. Thesubstrate is commonly glass, however alternative substrates may be used,in particular where flexibility of the device is desirable. For example,the substrate may comprise a plastic as in U.S. Pat. No. 6,268,695 whichdiscloses a substrate of alternating plastic and barrier layers or alaminate of thin glass and plastic as disclosed in EP 0949850.

Although not essential, the presence of a layer of organic holeinjection material over the anode is desirable as it assists holeinjection from the anode into the layer or layers of semiconductingpolymer. Examples of organic hole injection materials include PEDT/PSSas disclosed in EP 0901176 and EP 0947123, or polyaniline as disclosedin U.S. Pat. No. 5,723,873 and U.S. Pat. No. 5,798,170.

The cathode is selected in order that electrons are efficiently injectedinto the device and as such may comprise a single conductive materialsuch as a layer of aluminium. Alternatively, it may comprise a pluralityof metals, for example a bilayer of calcium and aluminium as disclosedin WO 98/10621, or a thin layer of dielectric material such as lithiumfluoride to assist electron injection as disclosed in, for example, WO00/48258. The device is preferably encapsulated with an encapsulant toprevent ingress of moisture and oxygen. Suitable encapsulants include asheet of glass, films having suitable barrier properties such asalternating stacks of polymer and dielectric as disclosed in, forexample, WO 01/81649 or an airtight container as disclosed in, forexample, WO 01/19142.

In a practical device, at least one of the electrodes issemi-transparent in order that light may be absorbed (in the case of aphotoresponsive device) or emitted (in the case of a PLED). Where theanode is transparent, it typically comprises indium tin oxide.

Examples of transparent cathodes are disclosed in, for example, GB2348316.

The PLED may be a static image device, i.e. a device that displays onlya single image. in the simplest case, the device comprises an anode,cathode and electroluminescent polymer, each of which are unpatterned.Such a device may be suitable for lighting applications or signsdisplaying a fixed image. Alternatively, the device may be a variableimage device, i.e. a device wherein different areas of theelectroluminescent layer may be independently addressed. Such a devicemay be a segmented, passive matrix or active matrix device.

Polymers formed by the method of the invention may also be used inswitching devices. In particular, they may be used in a field effecttransistor comprising an insulator having a first side and a secondside; a gate electrode located on the first side of the insulator; apolymer made by the method of the invention located on the second sideof the insulator; and a drain electrode and a source electrode locatedon the polymer. Unlike the aforementioned optoelectronic devices, itwill be appreciated that a transparent electrode is not a requirementfor a switching device. Such a field effect transistor may be used in anintegrated circuit.

EXAMPLES 2-(N-methyl-N-methoxyamido)-4,4′-dibromobiphenyl

NMR uses a Varian 400 MHz system, using CDCl₃ (unless indicatedotherwise) with a TMS standard.

(1) 2,7-Dibromofluorenone

To a 3 L round bottom flask, equipped with reflux condenser, off-gasscrubber, mechanical stirrer and nitrogen bubbler was added fluorenone(100.006 g, 0.555 mol), phosphorus pentoxide (110.148 g, 0.776 mol) andtrimethylphosphite (1200 mL). Under mechanical stirring, a solution ofbromine (63 mL, 1.23 mol) in trimethylphosphite (200 mL) was quicklyadded. This clear solution was then heated for 22 hours at 120° C. Themixture was allowed to cool to room temperature, then poured into 3 L ofwater. When sodium thiosulfate was added (50.045 g) the mixture turnedyellow. Stirring was maintained for 1 hour, then the yellow solid wasfiltered. This solid was heated in methanol to remove themono-brominated compound and gave 176.183 g (98% pure by HPLC, 94%yield).

¹H NMR (CDCl₃) 7.73 (2H, d, J2.0), 7.61 (2H, dd, J7.6, 2.0), 7.36 (2H,d, J8.0); ¹³C NMR (CDCl₃) 142.3, 137.5, 135.3, 127.9, 123.3, 121.8,109.8.

(2) 4,4′-Dibromo-2-carboxylic acid-1,1′-biphenyl

To a 5 L 3-necked flask, equipped with reflux condenser, nitrogenbubbler and overhead mechanical stirrer, was added 2,7-dibromofluorenone(533.0 g, 1.582 mol), potassium hydroxide (finely powdered flakes, 300.0g, 5.357 mol, 3.39 eq.) and toluene (3000 mL). The resulting mixture washeated at 120° C. for six hours then left to cool to room temperature.During this time, the appearance of the solution changed from a brightorange thin suspension into a completely white, thick suspension.

In a 10 L beaker, equipped with mechanical stirrer was added deionisedwater and then the cooled suspension was added over 3 minutes. Theresidual material in the flask was rinsed using extra toluene (2×500mL). The resulting mixture was stirred at room temperature for 30 mins,allowing the potassium salt to dissolve. The toluene phase was removedand extracted twice with deionised water (1000 mL). The toluene phasewas then discarded and the aqueous phases combined and acidified to pH1-3 using concentrated hydrochloric acid (10M) added dropwise from adropping funnel. During this time, the product evolved as a whitesuspension. The mixture was allowed to settle and the excess aqueousremoved by decantation. The resulting product slurry was then filteredand the cake rinsed with fresh water (1000 mL) until the liquors wereabout pH 3-4. The cake was air dried and then dried in vacuo for 18hours at 65° C. The product was afforded as an off-white solid (468 g,83%). ¹H NMR ((CD₃)₂CO) 8.00 (1H, d, J2.0), 7.77 (1H, dd, J8.0, 2.4),7.57 (2H, d, J8.0), 7.34 (1H, d, J8.4), 7.29 (2H, d, J8.8); ¹³C NMR((CD₃)₂CO) 167.1, 140.4, 139.8, 134.2, 133.5, 132.8, 132.7, 131.2,130.6, 121.4, 121.1.

(3) 4,4′-Dibromo-2-methyl ester-1,1′-biphenyl

To a 5 L 3-neck round-bottom flask, equipped with reflux condenser,nitrogen bubbler and mechanical stirrer was added4,4-dibromo-2-carboxylic (467.8 g, 1.264 mol) and methanol (3000 mL).Sulfuric acid (50 mL) was then added cautiously and the mixture thenheated to 90° C. for 21 hours. The suspended solid had all dissolvedafter this time to form a transparent solution. The solution was allowedto cool slightly (by about 10° C.) and then solid sodium carbonate (˜75g) added portionwise, until any sign of effervescence ceased. The hotsolution was stirred for 5 minutes then the stirrer stopped and thesolids allowed to settle. The hot solution was then decanted into a 5 Lround bottom flask equipped with mechanical stirrer (filtering was foundto cause rapid crystallisation of the product) and allowed tocrystallise overnight. The solid was collected by filtration and washedwith cold methanol. The solid was air dried and then dried in vacuo at45° C. The product was isolated as a white solid (354 g, 76%).

¹H NMR (CDCl₃) 7.99 (1H, d, J2.0), 7.64 (1H, dd, J8.0, 1.6), 7.51 (2H,d, J8.4), 7.19 (1H, d, J8.8), 7.13 (2H, d, J8.8), 3.67 (3H, s); ¹³C NMR(CDCl₃) 167.1, 140.3, 139.1, 134.4, 132.9, 132.1, 132.0, 131.3, 129.8,121.9, 121.5, 52.3. GCMS: M⁺=370, purity 99.5%+.

Literature ref: J.Am.Chem.Soc., 114, 15 (1992)

(4) Amide Intermediate: 2-(N,N-dimethylamido)-4,4′-dibromo-1,1′-biphenyl

To a 5 L 3-neck round-bottom flask, equipped with reflux condenser,nitrogen bubbler, 500 mL graduated pressure-equalised addition funnel,internal low temperature thermometer (−100 to +30° C.) and mechanicalstirrer was added 4,4-dibromo-2-methyl ester-1,1′-biphenyl (716.49 g,1.936 mol, 1.0 eq.) in anhydrous tetrahydrofuran (THF) (1500 mL). To thestirred solution was added N,N-dimethylhydroxylamine hydrochloride (288g, 3.0 mol, 1.55 eq.) and the resulting suspension cooled to −20° C.Iso-propylmagnesium chloride (2.0M in THF) was then added over about 1hour, ensuring the internal temperature of the mixture did not riseabout −5° C. The resulting solution was then allowed to warm to ambienttemperature over about 16 hours. The reaction mixture was carefullydiluted with toluene (2 L) and then quenched into a 10 L beakercontaining 5 L of 2M aqueous hydrochloric acid solution. The resultingmixture was stirred at ambient for 30 minutes and the toluene phaseseparated. The aqueous phase was extracted with toluene (2 L) and theorganic phases combined and evaporated to dryness in vacuo. Theresulting product was then triturated from Methanol (1500 mL). Theproduct (white solid) was collected by filtration and washed with coldMethanol (500 mL). The product was then dried for 16 hours in vacuo at45° C. The product was afforded as a white solid (521 g, 67%), purity99.5%+ by GCMS.

This amide, hereinafter referred to as amide 1 was used to prepare arange of asymmetric compounds according to the following scheme, whereinS1, S2 and M are as defined in the claims.

Ketone 1: 4,4′-Dibromo-1,1′-biphenyl-2-yl-4″-t-butylphenyl methanone

To a 3 L, 3-necked round bottom flask, equipped with mechanical stirrer,low temperature thermometer (−100 to +30° C.), nitrogen inlet andbubbler, and 500 mL graduated pressure-equalising dropping funnel, wasadded amide 1 (275.67 g, 0.691 mol, 1.0 eq.) and anhydrous THF (500 mL).The resulting suspension was stirred under nitrogen and cooled to −5° C.(MeOH-Cardice) and then tert-butylphenylmagnesium chloride (2M indiethyl ether, 380 mL, 0.76 mol, 1.1 eq.) was added at such a rate as tomaintain the internal temperature of the vessel between −5 and 0° C. Theresulting suspension was then allowed to warm to room temperature andstirred for 16 hours.

The reaction mixture was carefully diluted with toluene (1 L) pouredinto a 5 L beaker containing 2M aqueous hydrochloric acid solution (2 L)and the mixture-stirred by a mechanical stirrer for 30 minutes. Thestirrer was stopped and the layers allowed to settle. The organic phasewas removed by residual vacuum transfer and the aqueous phase extractedwith a further 1 L of toluene. The organic phases were combined andconcentrated to dryness in vacuo on a rotary evaporator. The resultingcrude product was suspended in methanol (1250 mL) and stirred at roomtemperature for 16 hours (trituration). The product was then recoveredby filtration using Buchner apparatus and the cake washed with freshmethanol (2×350 mL). The cake was air dried and the solid then dried at45° C. in vacuo for 16 hours.

The product ketone was afforded as a white solid (266.95 g, 74%). Theproduct was analysed by GC-MS and found to display m/z 472 (M+) and asingle peak (estimated purity 99.8%).

Asymmetric Compound 1 Precursor:4,4′-Dibromo-2-phenyl(4-tert-butylphenyl)hydroxymethyl-1,1′-biphenyl

To a 250 mL round bottomed flask, equipped with low temperaturethermometer (−100 to +30° C.), magnetic stirrer bar, 100 mL graduatedpressure-equalised dropping addition funnel and nitrogen inlet andbubbler was added bromobenzene (7.98 g, 5.35 mL, 50.82 mmol, 1.2 eq.)and anhydrous THF (50 mL) and the resulting solution cooled to −72° C.(acetone-cardice). N-Butyllithium (2.5M in hexanes) (22.02 mL, 55.06mmol, 1.3 eq.) was added dropwise, maintaining the internal temperaturebelow −65° C. After complete addition, the solution was maintained at−70° C. and stirred for 1 hour. A solution of ketone 1 (20.0 g, 42.35mmol, 1.0 eq.) in anhydrous THF (50.0 mL) was added, keeping theinternal temperature below −60° C. The solution was allowed to warm toroom temperature over 4 hours, then quenched into 2M aqueoushydrochloric acid solution (250 mL). The products were extracted intotoluene (2×250 mL), the organic phases combined and evaporated todryness in vacuo on a rotary evaporator. IPA was added (200 mL) and theproduct crystallised over 16 hours. The product was recovered byfiltration and the cake washed with cold isopropyl alcohol (50 mL). Theproduct was then air dried and dried at 45° C. in vacuo for 16 hours. Asecond crop was crystallised from the liquors.

The product was afforded as a white solid (18.63 g, 80%). The productwas analysed by GCMS and displayed an m/z-H₂O peak at m/z 532. Purityestimated at 99%₊.

Asymmetric Compound 1: 9-phenyl-9′-(tert-butylphenyl-2,7-dibromofluorene

To a 250 mL round bottomed flask, equipped with magnetic stirrer bar,reflux condenser and nitrogen inlet and bubbler was added asymmetriccompound 1 precursor (6.87 g, 12.5 mmol, 1.0 eq.) and glacial aceticacid (100 mL). To the stirred suspension at room temperature was addedconcentrated hydrochloric acid (2 mL) and the resulting suspensionheated to reflux. After 5 hours at reflux, in-process check indicatedthe reaction to be complete (GCMS). The solution was allowed to cool toroom temperature and poured into water (200 mL) with stirring for 10minutes. This caused precipitation of the product which was recovered byfiltration. The filter cake was washed with water (2×100 mL) and thendisplacement wash with methanol (100 mL). The crude product wasrecrystallised from a mixture of acetonitrile and toluene to affordasymmetric compound 1 as a white solid (3.2 g, 48%).

HPLC indicated 99.2% purity. GCMS indicated the correct product (m/z532).

Asymmetric Compound 2 Precursor:4,4′-Dibromo-2-biphenyl(tert-butylphenyl)hydroxymethyl-1,1′-biphenyl)

To a 250 mL round bottomed flask, equipped with low temperaturethermometer (−100 to +30° C.), magnetic stirrer bar, 100 mL graduatedpressure-equalised dropping addition funnel and nitrogen inlet andbubbler was added 4-bromobiphenyl (15.99 g, 68.6 mmol, 1.2 eq.) andanhydrous THF (100 mL) and the resulting solution cooled to −72° C.(acetone-Cardice). N-Butyllithium (2.5M in hexanes) (29.73 mL, 74.30mmol, 1.3 eq.) was added dropwise, maintaining the internal temperaturebelow −65° C. After complete addition, the solution was maintained at−70° C. and stirred for 1 hour. A solution of ketone 1 (27.0 g, 57.2mmol, 1.0 eq.) in anhydrous THF (75 mL) was added, keeping the internaltemperature <−60° C. The solution was allowed to warm to roomtemperature (RT) over 4 hours, and then quenched into 2M aqueoushydrochloric acid solution (500 mL). The products were extracted intotoluene (2×350 mL), and the organic phases combined and washed toneutrality with water (3×500 mL). The organic phases were combined andevaporated to dryness in vacuo on a rotary evaporator. Acetonitrile wasadded (200 mL) and the product crystallised over 16 hours. The productwas recovered by filtration and the cake washed with cold acetonitrile(50 mL). The product was air dried and then dried at 45° C. in vacuo for16 hours. A second crop was crystallised from the liquors.

The product was afforded as a white solid (26.5 g, 74%). The product wasanalysed by GCMS and displayed an m/z-H₂O peak at m/z 611. Purityestimated at 95%+.

Asymmetric Compound 2:9-biphenyl-9-(4-tert-butylphenyl)-2,7-dibromofluorene

To a 250 mL round bottomed flask, equipped with magnetic stirrer bar,reflux condenser and nitrogen inlet and bubbler was added the asymmetriccompound 2 precursor (26 g, 41.5 mmol, 1.0 eq.) and glacial acetic acid(500 mL). To the stirred suspension at room temperature was addedconcentrated hydrochloric acid (1 mL) and the resulting suspensionheated to reflux. After 2 hours at reflux, in-process check indicatedthe reaction to be complete (GCMS). The solution was allowed to cool toroom temperature and poured into water (2 L) with stirring for 10minutes. This caused precipitation of the product which was recovered byfiltration. The filter cake was washed with water (3×1 L) and thendisplacement wash with methanol (500 mL). The crude product wasrecrystallised from a mixture of acetonitrile and toluene to afford theproduct as a white solid (13.7 g, 54%). HPLC indicated 99.42% purity.GCMS indicated the correct product (m/z 609).

Asymmetric Compound 3 Precursor:4,4′-Dibromo-2-(4′-tert-butyl-1,1′-biphenyl)-(tert-butylphenyl)hydroxymethyl-1,1′-biphenyl

To a 500 mL round bottomed flask, equipped with low temperaturethermometer (−100 to +30° C.), mechanical stirrer, 100 mL graduatedpressure-equalised dropping addition funnel and nitrogen inlet andbubbler was added 4-tert-butyl-4′-bromo-1,1′-biphenyl (11.36 g, 39.28mmol, 1.2 eq.) and anhydrous THF (100 mL) and the resulting solutioncooled to −72° C. (acetone-Cardice). N-Butyllithium (2.5M in hexanes)(21.28 mL, 42.55 mmol, 1.3 eq.) was added dropwise, maintaining theinternal temperature below −65° C. After complete addition, the solutionwas maintained at −70° C. and stirred for 1 hour. A solution of ketone 1(15.45 g, 32.73 mmol, 1.0 eq.) in anhydrous THF (125.0 mL) was added,keeping the internal temperature <−60° C. The solution was allowed towarm to RT over 4 hours, then quenched into 2M aqueous hydrochloric acidsolution (500 mL). The products were extracted into toluene (2×500 mL),the organic phases combined and washed with water to neutrality (3×500mL). The toluene phase was evaporated to dryness in vacuo on a rotaryevaporator. Acetonitrile was added (200 mL) and the product crystallisedover 16 hours. The product was recovered by filtration and the cakewashed with cold IPA (50 mL). The product was then air dried and driedat 45° C. in vacuo for 16 hours. A second crop was crystallised from theliquors.

The product was afforded as a white solid (14 g, 52%). Purity estimatedat 99%+.

Asymmetric Compound 3:9-(4′-tert-butyl-1,1′-biphenyl)-9-(4-tert-butylphenyl)-2,7-dibromofluorene

To a 1 L round bottomed flask, equipped with magnetic stirrer bar,reflux condenser and nitrogen inlet and bubbler was added asymmetriccompound 3 precursor (14 g, 20.5 mmol, 1.0 eq.) and glacial acetic acid(500 mL). To the stirred suspension at room temperature was addedconcentrated hydrochloric acid (2 mL) and the resulting suspensionheated to reflux. After 3 hours at reflux, in-process check indicatedthe reaction to be complete (GCMS). The solution was allowed to cool toroom temperature and poured into water (2 L) with stirring for 10minutes. This caused precipitation of the product which was recovered byfiltration. The filter cake was washed with water (2×1 L). The crudeproduct was recrystallised from a mixture of acetonitrile and toluene toafford asymmetric compound 3 as a white solid (10.63 g, 78%).

HPLC indicated 99.6% purity. GCMS indicated the correct product (m/z664).

Asymmetric Compound 4 Precursor:4,4′-dibromo-2-(4-tert-butylphenyl)-2-thienyl-hydroxymethyl-1,1′-biphenyl

To a 500 mL round bottomed flask, equipped with low temperaturethermometer (−100 to +30° C.), mechanical stirrer, 100 mL graduatedpressure-equalised dropping addition funnel and nitrogen inlet andbubbler was added 2-bromothiophene (6.21 g, 38.11 mmol, 1.2 eq.) andanhydrous THF (100 mL) and the resulting solution cooled to −72° C.(acetone-cardice). N-Butyllithium (2.5M in hexanes) (20.64 mL, 41.29mmol, 1.3 eq.) was added dropwise, maintaining the internal temperaturebelow −65° C. After complete addition, the solution was maintained at−70° C. and stirred for 1 hour. A solution of ketone 1 (15.0 g, 31.76mmol, 1.0 eq.) in anhydrous THF (125.0 mL) was added, keeping theinternal temperature <−60° C. The solution was allowed to warm to RTover 4 hours, then quenched into 2M aqueous hydrochloric acid solution(500 mL). The products were extracted into toluene (2×300 mL), theorganic phases combined and washed with water to neutrality (3×500 mL).The toluene phase was evaporated to dryness in vacuo on a rotaryevaporator. The product was purified by column chromatography using amixture of dichloromethane and hexanes (1:1).

The product was afforded as a red solid (15 g, 72%). The product wasanalysed by GCMS and displayed an m/z-H₂O peak at m/z 538. Purityestimated at 96.8%+.

Asymmetric Compound 4:9-(4-tert-butylphenyl)-9-thien-2-yl-2,7-dibromofluorene

To a 500 mL round bottomed flask, equipped with magnetic stirrer bar,reflux condenser and nitrogen inlet and bubbler was added the asymmetriccompound 4 precursor (15.1 g, 27.15 mmol, 1.0 eq.) and glacial aceticacid (500 mL). To the stirred suspension at room temperature was addedconcentrated hydrochloric acid (2 mL) and the resulting suspensionheated to reflux. After 4 hours at reflux, in-process check indicatedthe reaction to be complete (GCMS). The solution was allowed to cool toroom temperature and poured into water (1000 mL) with stirring for 10minutes. This caused precipitation of the product which was recovered byfiltration. The filter cake was washed with water (2×1 L). The crudeproduct was triturated from hexanes to afford asymmetric compound 4 as adark solid (14 g, 90%).

HPLC indicated >80% purity.

Ketone 2: [4,4-dibromo-1,1′-biphenyl]-2-yl-n-octyl ketone

To a 500 mL round bottomed 3-necked flask, equipped with mechanicalstirrer, reflux condenser, 100 mL pressure-equalised dropping additionfunnel, nitrogen inlet and bubbler and low temperature thermometer (−100to +30° C.) was added amide 1 (30.0 g, 75.2 mmol, 1.0 eq.) and anhydrousTHF (200 mL). The resulting solution was stirred under nitrogen andcooled to −20° C. (MeOH-cardice). A solution of n-octylmagnesium bromide(2.0M in THF, 48.7 mL, 97.7 mmol, 1.3 eq.) was added dropwise,maintaining the internal solution temperature below −10° C. Aftercomplete addition, the solution was allowed to warm to room temperatureovernight. The reaction mixture was poured into 2M aqueous hydrochloricacid solution (500 mL) and the products extracted into toluene (2×300mL). The toluene extracts were washed with water (3×500 mL). The toluenephase was then concentrated to dryness in vacuo using a rotaryevaporator.

The crude product was purified using column chromatography using 100%hexanes to 4:1 dichloromethane:hexanes as eluant. Product was isolatedas an oil (22.91 g, 67.4%). GCMS indicated m/z 452, purity almost 100%.

Asymmetric Compound 5 Precursor:4,4′-Dibromo-2-n-octyl-2-phenylhydroxymethyl-1,1′-biphenyl

To a 500 mL round bottomed flask, equipped with low temperaturethermometer (−100 to +30° C.), mechanical stirrer, 100 mL graduatedpressure-equalised dropping addition funnel and nitrogen inlet andbubbler was added bromobenzene (9.55 g, 60.79 mmol, 1.2 eq.) andanhydrous THF (150 mL) and the resulting solution cooled to −72° C.(acetone-cardice). N-Butyllithium (2.5M in hexanes) (26.34 mL, 65.86mmol, 1.3 eq.) was added dropwise, maintaining the internal temperaturebelow −65° C. After complete addition, the solution was maintained at−70° C. and stirred for 1 hour. A solution of ketone 2 (22.91 g, 50.66mmol, 1.0 eq.) in anhydrous THF (125.0 mL) was added, keeping theinternal temperature <−60° C. The solution was allowed to warm to RTover 4 hours, then quenched into 2M aqueous hydrochloric acid solution(500 mL). The products were extracted into toluene (2×300 mL), theorganic phases combined and washed with water to neutrality (3×500 mL).The toluene phase was evaporated to dryness in vacuo on a rotaryevaporator. The product was purified by column chromatography using amixture of dichloromethane and hexanes (1:4).

The product was afforded as a colourless oil (12.1 g, 45%). The productwas analysed by GCMS and displayed an m/z-H_(ny)O peak at m/z 512.Purity estimated at 87%+.

Asymmetric Compound 5: 9-n-octyl-9-phenyl-2,7-dibromofluorene

To a 500 mL round bottomed flask, equipped with magnetic stirrer bar,reflux condenser and nitrogen inlet and bubbler was added the asymmetriccompound 5 precursor (12.1 g, 22.83 mmol, 1.0 eq.) and glacial aceticacid (500 mL). To the stirred suspension at room temperature was addedconcentrated hydrochloric acid (2 mL) and the resulting suspensionheated to reflux. After 4 hours at reflux, in-process check by GCMSindicated the reaction to be complete. The solution was allowed to coolto room temperature and poured into water (1 L) with stirring for 10minutes. This caused precipitation of the product which was recovered byfiltration. The filter cake was washed with water (2×1 L). The crudeproduct was triturated from hexanes to afford asymmetric compound 5 asan oil (10 g, 83%).

GCMS indicated 97.06% purity.

Ketone 3: [4,4′-Dibromo-1,1′-biphenyl]-2-yl phenyl ketone

To a 2 L, 3-necked round bottom flask, equipped with mechanical stirrer,low temperature thermometer (−100 to +30° C.), nitrogen inlet andbubbler, and 500 mL graduated pressure-equalising dropping funnel, wasadded amide 1 (150 g, 0.376 mol, 1.0 eq.) and anhydrous THF (500 mL).The resulting solution was stirred under nitrogen and cooled to −5° C.(MeOH-cardice) and then phenylmagnesium bromide (3M in THF, 140 mL,0.414 mol, 1.1 eq.) was added at such a rate as to maintain the internaltemperature of the vessel between −5 and 0° C. The resulting suspensionwas then allowed to warm to room temperature and stirred for 16 hours.

The reaction mixture was carefully diluted with toluene (1 L) pouredinto a 5 L beaker containing 2M aqueous hydrochloric acid solution (2 L)and the mixture stirred by a mechanical stirrer for 30 minutes. Thestirrer was stopped and the layers allowed to settle. The organic phasewas removed by residual vacuum transfer and the aqueous phase extractedwith a further 1 L of toluene. The organic phases were combined andconcentrated to dryness in vacuo on a rotary evaporator. The resultingcrude product was suspended in methanol (750 mL) and stirred at roomtemperature for 16 hours (trituration). The product was then recoveredby filtration using Buchner apparatus and the cake washed with freshmethanol (2×250 mL). The cake was air dried and the solid then dried at45° C. in vacuo for 16 hours.

The product ketone was afforded as a white solid (147.84 g, 94%). Theproduct was analysed by GC-MS and found to display m/z 416 (M+) and asingle peak (estimated purity 99.8%).

Asymmetric Compound 6 Precursor:4,4′-dibromo-2-phenyl(4-decyloxyphenyl)hydroxymethyl-1,1′-biphenyl)

To a 250 mL round bottomed flask, equipped with low temperaturethermometer (−100 to +30° C.), magnetic stirrer bar, 100 mL graduatedpressure-equalised dropping addition funnel and nitrogen inlet andbubbler was added 4-decyloxybenzene (16.5 g, 53.0 mmol, 1.1 q.) andanhydrous THF (100 mL) and the resulting solution cooled to −72° C.(acetone-cardice). N-Butyllithium (2.5M in hexanes) (23.0 mL, 58.0 mmol,1.2 eq.) was added dropwise, maintaining the internal temperature below−65° C. After complete addition, the solution was maintained at −70° C.and stirred for 1 hour. A solution of ketone 3 (20.0 g, 48.0 mmol, 1.0eq.) in anhydrous THF (50.0 mL) was added, keeping the internaltemperature <−60° C. The solution was allowed to warm to RT over 4hours, then quenched into 2M aqueous hydrochloric acid solution (250mL). The products were extracted into toluene (2×250 mL), the organicphases combined and evaporated to dryness in vacuo on a rotaryevaporator. Isopropyl alcohol was added (200 mL) and the productcrystallised over 16 hours. The product was recovered by filtration andthe cake washed with cold isopropyl alcohol (50 mL). The product wasthen air dried and dried at 45° C. in vacuo for 16 hours.

The product was afforded as a white solid (18.6 g, 90%). The product asanalysed by GCMS showed a mixture of products.

Asymmetric Compound 6 Precursor:2,7-dibromo-9-phenyl-9-(4-decyloxyphenyl)fluorene

Asymmetric compound 6 was prepared by dehydration of asymmetric compound5 according to the method described above for the preparation ofasymmetric compound 1.

Pinacol diester of Asymmetric Compound 1 (Method 1):9-phenyl-9-tert-butylphenylfluorene-2,7-pinacolatoboron ester

To a 3-necked round bottomed 2 L flask, equipped with mechanicalstirrer, reflux condenser, nitrogen inlet and bubbler, low temperaturethermometer (−100 to +30° C.) and pressure-equalised, 250 mL graduateddropping addition funnel (inerted with nitrogen before use) was addedasymmetric compound 1 (54.97 g, 0.103 mol, 1.0 eq.) and anhydrous THF(550 mL). The resulting solution was cooled to −78° C. (acetone-cardice)and n-butyllithium (2.5M in hexanes) (90.64 mL, 0.227 mol, 2.2 eq.) wasadded dropwise so as to maintain the internal temperature below −65° C.After complete addition, the solution was stirred at −78 warming up to8° C. for a further 1 hour, before the addition of triisopropylborate(58.12 g, 71 mL, 0.309 mol, 3.0 eq.) dissolved in anhydrous THF (160mL), again maintaining the internal temperature below −65° C. Theresulting solution was then allowed to warm slowly to room temperature.

The solution was cooled to 0° C. (ice-water) and HCl in ether solution(2M) (134 mL, 0.27 mol, 2.6 eq.) was added and the solution allowed towarm to room temperature before filtering through a No. 3 porositysinter funnel (to remove precipitated inorganic salts). The solvent wasremoved in vacuo and the residue re-dissolved in toluene (250 mL). Thesolution was cooled and filtered (paper) into a 1 L flask. Pinacol(58.12 g, 0.27 mol, 3.0 eq.) was added, followed by para-toluenesulfonicacid (1 g) and the reaction heated under Dean-Stark conditions for 4hours. The solution was allowed to cool and 2 g of potassium carbonateadded. The mixture was stirred for 30 minutes at RT, filtered and thesolution concentrated to dryness in vacuo. The solid was recrystallisedfrom a toluene/acetonitrile mixture to afford the product, which wasrecovered by filtration.

The product was dried at 45° C. for 16 hours. The title compound wasafforded as a white solid (43 g, 66%). HPLC indicated a purity (npa) of93%.

Pinacol diester of Asymmetric Compound 1 (Method 2):9-phenyl-9-tert-butylphenylfluorene-2,7-pinacolatoboron ester

To a 500 mL 3 neck round bottomed flask, equipped with reflux condenser,mechanical stirrer and septum cap (cooled under nitrogen before use) wasadded asymmetric compound 1 (33 g, 62 mmol, 1.0 eq.), anhydrous toluene(400 mL), PdCl₂[(o-tol)₃P]₂ (2.44 g, 3.1 mmol, 5 mol %) andortho-tolylphosphine (1.89 g, 10 mol %). The solution was degassed bysparging with nitrogen for 1 hour, then triethylamine (37.64 g, 0.186mmol, 6.0 eq.) added, followed by degassing for 15 minutes.Pinacolborane (23.80 g, 0.186 mol, 3.0 eq.) was then added and thesolution heated to reflux for 4 hours. The reaction mixture was allowedto cool to room temperature and then filtered through a short pad ofsilica gel, eluting with toluene (500 mL). The toluene solution wasconcentrated to dryness in vacuo. The crude solid was then purified byrecrystallisation from a toluene/acetonitrile mixture to afford theproduct, which was recovered by filtration.

The product was dried at 45° C. for 16 hours. The title compound wasafforded as a white solid (15 g, 39%). HPLC indicated a purity (npa) of99%. GC-MS indicated the correct mass (m/z 626).

COMPARATIVE EXAMPLE

Synthesis of ketone 1 was attempted in accordance with the methoddescribed above, except that ester 1, shown below, was used in place ofamide 1:

The product mixture was found to comprise starting material, ketone 1and the alcohol resulting from over-reaction of ketone 1 with theGrignard reagent. Difficulty was encountered in attempting to separatethese products.

Although the present invention has been described in terms of specificexemplary embodiments, it will be appreciated that variousmodifications, alterations and/or combinations of features disclosedherein will be apparent to those skilled in the art without departingfrom the spirit and scope of the invention as set forth in the followingclaims.

1. A method of forming a compound of formula (IV):

said method comprising the steps of: a) reacting a compound of formula(I) with a compound of formula S¹-M to give a compound of formula (II);b) reacting the compound of formula (II) with a compound of formula S²-Mto give a compound of formula (III); and c) eliminating H₂X from thecompound of formula (III) to give a compound of formula (IV), whereinAr¹ and Ar² are independently selected from optionally substituted arylor heteroaryl groups; X is O, S, NH or NR; L is a bond or a linkinggroup which contains 1, 2 or 3 atoms; R and R₁ are independentlyselected from the group consisting of optionally substituted alkyl,aryl, alkylaryl, arylalkyl and heteroaryl groups; R₂ is selected fromthe group consisting of alkoxy, aryloxy, arylalkyloxy, alkylaryloxy,alkylthio, arylthio, alkylarylthio and arylalkylthio; H is bound to acarbon atom C′ of Ar²; C′ and the carbon atom of C═X are separated by3-5 atoms; S¹ and S² are each selected from optionally substitutedalkyl, aryl or heteroaryl groups, M comprises a metal; and M is linkedto S¹ and S² by a carbon-metal bond.
 2. A method according to claim 1wherein alkyl is C₁-C₂₀-alkyl, arylalkyl is C₇-C₂₀-arylalkyl, alkylarylis C₇-C₂₀-alkylaryl, aryl is C₆-C₂₀-aryl, heteroaryl isC₅-C₂₀-heteroaryl, alkoxy is C₁-C₂₀-alkoxy, aryloxy is C₆-C₂₀-Aryloxy,arylalkyloxy is C₇-C₂₀-arylalkyloxy, alkylaryloxy isC₇-C₂₀-alkylaryloxy, alkylthio is C₁-C₂₀-alkylthio, arylthio isC₆-C₂₀-arylthio, alkylarylthio is C₇-C₂₀-alkylarylthio, arylalkylthio isC₇-C₂₀-arylalkylthio.
 3. A method according to claim 1 wherein Ar¹ andAr² are phenyl or substituted phenyl.
 4. A method according to claim 1,wherein X is O or S.
 5. A method according to claim 1, wherein L is abond.
 6. A method according to claim 1, wherein R is C1-10 alkyl.
 7. Amethod according to claim 1, wherein R¹ is C1-10 alkyl.
 8. A methodaccording to claim 1, wherein R² is C1-10 alkoxy.
 9. A method accordingto claim 1, wherein M is lithium, zinc or Mg-Hal wherein Hal is ahalide.
 10. A method according to claim 1, wherein S¹ and S² areindependently selected from optionally substituted aryl or alkyl.
 11. Amethod according to claim 1, wherein S¹ and S² are independentlyselected from optionally substituted aryl or alkyl and S¹ and S² aredifferent from each other.
 12. A method according to claim 1, whereinAr¹ and Ar² of the compound of formula (I) are each substituted with apolymerisable group P.
 13. A method according to claim 1, comprising thefurther step of providing each of Ar¹ and Ar² of the compound of formula(II), (III) or (IV) with a polymerisable group P.
 14. A method accordingto claim 12, wherein each polymerisable group P is independently ahalide or a boron derivative group selected from a boronic acid group, aboronic ester group and a borane group; or a moiety of formula —O—SO₂-Zwherein Z is selected from the group consisting of optionallysubstituted alkyl and aryl.
 15. A method according to claim 12 whereineach polymerisable group P is independently a leaving group capable ofparticipating in a polycondensation reaction.
 16. A method according toclaim 1 wherein Ar¹ and Ar² are phenyl or substituted phenyl, X is O orS, L is a bond, R is C1-10 alkyl, R¹ is C1-10 alkyl, R² is C1-10 alkoxy,M is lithium, zinc or Mg-Hal wherein Hal is a halide, S¹ and S² areindependently selected from optionally substituted aryl or alkyl and S¹and S² are are different from each other.